golang.org/toolchain@v0.0.1-go1.9rc2.windows-amd64/src/syscall/syscall_windows.go (about)

     1  // Copyright 2009 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Windows system calls.
     6  
     7  package syscall
     8  
     9  import (
    10  	errorspkg "errors"
    11  	"internal/race"
    12  	"sync"
    13  	"unicode/utf16"
    14  	"unsafe"
    15  )
    16  
    17  type Handle uintptr
    18  
    19  const InvalidHandle = ^Handle(0)
    20  
    21  // StringToUTF16 returns the UTF-16 encoding of the UTF-8 string s,
    22  // with a terminating NUL added. If s contains a NUL byte this
    23  // function panics instead of returning an error.
    24  //
    25  // Deprecated: Use UTF16FromString instead.
    26  func StringToUTF16(s string) []uint16 {
    27  	a, err := UTF16FromString(s)
    28  	if err != nil {
    29  		panic("syscall: string with NUL passed to StringToUTF16")
    30  	}
    31  	return a
    32  }
    33  
    34  // UTF16FromString returns the UTF-16 encoding of the UTF-8 string
    35  // s, with a terminating NUL added. If s contains a NUL byte at any
    36  // location, it returns (nil, EINVAL).
    37  func UTF16FromString(s string) ([]uint16, error) {
    38  	for i := 0; i < len(s); i++ {
    39  		if s[i] == 0 {
    40  			return nil, EINVAL
    41  		}
    42  	}
    43  	return utf16.Encode([]rune(s + "\x00")), nil
    44  }
    45  
    46  // UTF16ToString returns the UTF-8 encoding of the UTF-16 sequence s,
    47  // with a terminating NUL removed.
    48  func UTF16ToString(s []uint16) string {
    49  	for i, v := range s {
    50  		if v == 0 {
    51  			s = s[0:i]
    52  			break
    53  		}
    54  	}
    55  	return string(utf16.Decode(s))
    56  }
    57  
    58  // StringToUTF16Ptr returns pointer to the UTF-16 encoding of
    59  // the UTF-8 string s, with a terminating NUL added. If s
    60  // contains a NUL byte this function panics instead of
    61  // returning an error.
    62  //
    63  // Deprecated: Use UTF16PtrFromString instead.
    64  func StringToUTF16Ptr(s string) *uint16 { return &StringToUTF16(s)[0] }
    65  
    66  // UTF16PtrFromString returns pointer to the UTF-16 encoding of
    67  // the UTF-8 string s, with a terminating NUL added. If s
    68  // contains a NUL byte at any location, it returns (nil, EINVAL).
    69  func UTF16PtrFromString(s string) (*uint16, error) {
    70  	a, err := UTF16FromString(s)
    71  	if err != nil {
    72  		return nil, err
    73  	}
    74  	return &a[0], nil
    75  }
    76  
    77  // Errno is the Windows error number.
    78  type Errno uintptr
    79  
    80  func langid(pri, sub uint16) uint32 { return uint32(sub)<<10 | uint32(pri) }
    81  
    82  // FormatMessage is deprecated (msgsrc should be uintptr, not uint32, but can
    83  // not be changed due to the Go 1 compatibility guarantee).
    84  //
    85  // Deprecated: Use FormatMessage from golang.org/x/sys/windows instead.
    86  func FormatMessage(flags uint32, msgsrc uint32, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) {
    87  	return formatMessage(flags, uintptr(msgsrc), msgid, langid, buf, args)
    88  }
    89  
    90  func (e Errno) Error() string {
    91  	// deal with special go errors
    92  	idx := int(e - APPLICATION_ERROR)
    93  	if 0 <= idx && idx < len(errors) {
    94  		return errors[idx]
    95  	}
    96  	// ask windows for the remaining errors
    97  	var flags uint32 = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY | FORMAT_MESSAGE_IGNORE_INSERTS
    98  	b := make([]uint16, 300)
    99  	n, err := formatMessage(flags, 0, uint32(e), langid(LANG_ENGLISH, SUBLANG_ENGLISH_US), b, nil)
   100  	if err != nil {
   101  		n, err = formatMessage(flags, 0, uint32(e), 0, b, nil)
   102  		if err != nil {
   103  			return "winapi error #" + itoa(int(e))
   104  		}
   105  	}
   106  	// trim terminating \r and \n
   107  	for ; n > 0 && (b[n-1] == '\n' || b[n-1] == '\r'); n-- {
   108  	}
   109  	return string(utf16.Decode(b[:n]))
   110  }
   111  
   112  func (e Errno) Temporary() bool {
   113  	return e == EINTR || e == EMFILE || e == WSAECONNABORTED || e == WSAECONNRESET || e.Timeout()
   114  }
   115  
   116  func (e Errno) Timeout() bool {
   117  	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
   118  }
   119  
   120  // Implemented in runtime/syscall_windows.go.
   121  func compileCallback(fn interface{}, cleanstack bool) uintptr
   122  
   123  // Converts a Go function to a function pointer conforming
   124  // to the stdcall calling convention. This is useful when
   125  // interoperating with Windows code requiring callbacks.
   126  func NewCallback(fn interface{}) uintptr {
   127  	return compileCallback(fn, true)
   128  }
   129  
   130  // Converts a Go function to a function pointer conforming
   131  // to the cdecl calling convention. This is useful when
   132  // interoperating with Windows code requiring callbacks.
   133  func NewCallbackCDecl(fn interface{}) uintptr {
   134  	return compileCallback(fn, false)
   135  }
   136  
   137  // windows api calls
   138  
   139  //sys	GetLastError() (lasterr error)
   140  //sys	LoadLibrary(libname string) (handle Handle, err error) = LoadLibraryW
   141  //sys	FreeLibrary(handle Handle) (err error)
   142  //sys	GetProcAddress(module Handle, procname string) (proc uintptr, err error)
   143  //sys	GetVersion() (ver uint32, err error)
   144  //sys	formatMessage(flags uint32, msgsrc uintptr, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) = FormatMessageW
   145  //sys	ExitProcess(exitcode uint32)
   146  //sys	CreateFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) [failretval==InvalidHandle] = CreateFileW
   147  //sys	ReadFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error)
   148  //sys	WriteFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error)
   149  //sys	SetFilePointer(handle Handle, lowoffset int32, highoffsetptr *int32, whence uint32) (newlowoffset uint32, err error) [failretval==0xffffffff]
   150  //sys	CloseHandle(handle Handle) (err error)
   151  //sys	GetStdHandle(stdhandle int) (handle Handle, err error) [failretval==InvalidHandle]
   152  //sys	findFirstFile1(name *uint16, data *win32finddata1) (handle Handle, err error) [failretval==InvalidHandle] = FindFirstFileW
   153  //sys	findNextFile1(handle Handle, data *win32finddata1) (err error) = FindNextFileW
   154  //sys	FindClose(handle Handle) (err error)
   155  //sys	GetFileInformationByHandle(handle Handle, data *ByHandleFileInformation) (err error)
   156  //sys	GetCurrentDirectory(buflen uint32, buf *uint16) (n uint32, err error) = GetCurrentDirectoryW
   157  //sys	SetCurrentDirectory(path *uint16) (err error) = SetCurrentDirectoryW
   158  //sys	CreateDirectory(path *uint16, sa *SecurityAttributes) (err error) = CreateDirectoryW
   159  //sys	RemoveDirectory(path *uint16) (err error) = RemoveDirectoryW
   160  //sys	DeleteFile(path *uint16) (err error) = DeleteFileW
   161  //sys	MoveFile(from *uint16, to *uint16) (err error) = MoveFileW
   162  //sys	GetComputerName(buf *uint16, n *uint32) (err error) = GetComputerNameW
   163  //sys	SetEndOfFile(handle Handle) (err error)
   164  //sys	GetSystemTimeAsFileTime(time *Filetime)
   165  //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) [failretval==0xffffffff]
   166  //sys	CreateIoCompletionPort(filehandle Handle, cphandle Handle, key uint32, threadcnt uint32) (handle Handle, err error)
   167  //sys	GetQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) (err error)
   168  //sys	PostQueuedCompletionStatus(cphandle Handle, qty uint32, key uint32, overlapped *Overlapped) (err error)
   169  //sys	CancelIo(s Handle) (err error)
   170  //sys	CancelIoEx(s Handle, o *Overlapped) (err error)
   171  //sys	CreateProcess(appName *uint16, commandLine *uint16, procSecurity *SecurityAttributes, threadSecurity *SecurityAttributes, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation) (err error) = CreateProcessW
   172  //sys	OpenProcess(da uint32, inheritHandle bool, pid uint32) (handle Handle, err error)
   173  //sys	TerminateProcess(handle Handle, exitcode uint32) (err error)
   174  //sys	GetExitCodeProcess(handle Handle, exitcode *uint32) (err error)
   175  //sys	GetStartupInfo(startupInfo *StartupInfo) (err error) = GetStartupInfoW
   176  //sys	GetCurrentProcess() (pseudoHandle Handle, err error)
   177  //sys	GetProcessTimes(handle Handle, creationTime *Filetime, exitTime *Filetime, kernelTime *Filetime, userTime *Filetime) (err error)
   178  //sys	DuplicateHandle(hSourceProcessHandle Handle, hSourceHandle Handle, hTargetProcessHandle Handle, lpTargetHandle *Handle, dwDesiredAccess uint32, bInheritHandle bool, dwOptions uint32) (err error)
   179  //sys	WaitForSingleObject(handle Handle, waitMilliseconds uint32) (event uint32, err error) [failretval==0xffffffff]
   180  //sys	GetTempPath(buflen uint32, buf *uint16) (n uint32, err error) = GetTempPathW
   181  //sys	CreatePipe(readhandle *Handle, writehandle *Handle, sa *SecurityAttributes, size uint32) (err error)
   182  //sys	GetFileType(filehandle Handle) (n uint32, err error)
   183  //sys	CryptAcquireContext(provhandle *Handle, container *uint16, provider *uint16, provtype uint32, flags uint32) (err error) = advapi32.CryptAcquireContextW
   184  //sys	CryptReleaseContext(provhandle Handle, flags uint32) (err error) = advapi32.CryptReleaseContext
   185  //sys	CryptGenRandom(provhandle Handle, buflen uint32, buf *byte) (err error) = advapi32.CryptGenRandom
   186  //sys	GetEnvironmentStrings() (envs *uint16, err error) [failretval==nil] = kernel32.GetEnvironmentStringsW
   187  //sys	FreeEnvironmentStrings(envs *uint16) (err error) = kernel32.FreeEnvironmentStringsW
   188  //sys	GetEnvironmentVariable(name *uint16, buffer *uint16, size uint32) (n uint32, err error) = kernel32.GetEnvironmentVariableW
   189  //sys	SetEnvironmentVariable(name *uint16, value *uint16) (err error) = kernel32.SetEnvironmentVariableW
   190  //sys	SetFileTime(handle Handle, ctime *Filetime, atime *Filetime, wtime *Filetime) (err error)
   191  //sys	GetFileAttributes(name *uint16) (attrs uint32, err error) [failretval==INVALID_FILE_ATTRIBUTES] = kernel32.GetFileAttributesW
   192  //sys	SetFileAttributes(name *uint16, attrs uint32) (err error) = kernel32.SetFileAttributesW
   193  //sys	GetFileAttributesEx(name *uint16, level uint32, info *byte) (err error) = kernel32.GetFileAttributesExW
   194  //sys	GetCommandLine() (cmd *uint16) = kernel32.GetCommandLineW
   195  //sys	CommandLineToArgv(cmd *uint16, argc *int32) (argv *[8192]*[8192]uint16, err error) [failretval==nil] = shell32.CommandLineToArgvW
   196  //sys	LocalFree(hmem Handle) (handle Handle, err error) [failretval!=0]
   197  //sys	SetHandleInformation(handle Handle, mask uint32, flags uint32) (err error)
   198  //sys	FlushFileBuffers(handle Handle) (err error)
   199  //sys	GetFullPathName(path *uint16, buflen uint32, buf *uint16, fname **uint16) (n uint32, err error) = kernel32.GetFullPathNameW
   200  //sys	GetLongPathName(path *uint16, buf *uint16, buflen uint32) (n uint32, err error) = kernel32.GetLongPathNameW
   201  //sys	GetShortPathName(longpath *uint16, shortpath *uint16, buflen uint32) (n uint32, err error) = kernel32.GetShortPathNameW
   202  //sys	CreateFileMapping(fhandle Handle, sa *SecurityAttributes, prot uint32, maxSizeHigh uint32, maxSizeLow uint32, name *uint16) (handle Handle, err error) = kernel32.CreateFileMappingW
   203  //sys	MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error)
   204  //sys	UnmapViewOfFile(addr uintptr) (err error)
   205  //sys	FlushViewOfFile(addr uintptr, length uintptr) (err error)
   206  //sys	VirtualLock(addr uintptr, length uintptr) (err error)
   207  //sys	VirtualUnlock(addr uintptr, length uintptr) (err error)
   208  //sys	TransmitFile(s Handle, handle Handle, bytesToWrite uint32, bytsPerSend uint32, overlapped *Overlapped, transmitFileBuf *TransmitFileBuffers, flags uint32) (err error) = mswsock.TransmitFile
   209  //sys	ReadDirectoryChanges(handle Handle, buf *byte, buflen uint32, watchSubTree bool, mask uint32, retlen *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) = kernel32.ReadDirectoryChangesW
   210  //sys	CertOpenSystemStore(hprov Handle, name *uint16) (store Handle, err error) = crypt32.CertOpenSystemStoreW
   211  //sys   CertOpenStore(storeProvider uintptr, msgAndCertEncodingType uint32, cryptProv uintptr, flags uint32, para uintptr) (handle Handle, err error) [failretval==InvalidHandle] = crypt32.CertOpenStore
   212  //sys	CertEnumCertificatesInStore(store Handle, prevContext *CertContext) (context *CertContext, err error) [failretval==nil] = crypt32.CertEnumCertificatesInStore
   213  //sys   CertAddCertificateContextToStore(store Handle, certContext *CertContext, addDisposition uint32, storeContext **CertContext) (err error) = crypt32.CertAddCertificateContextToStore
   214  //sys	CertCloseStore(store Handle, flags uint32) (err error) = crypt32.CertCloseStore
   215  //sys   CertGetCertificateChain(engine Handle, leaf *CertContext, time *Filetime, additionalStore Handle, para *CertChainPara, flags uint32, reserved uintptr, chainCtx **CertChainContext) (err error) = crypt32.CertGetCertificateChain
   216  //sys   CertFreeCertificateChain(ctx *CertChainContext) = crypt32.CertFreeCertificateChain
   217  //sys   CertCreateCertificateContext(certEncodingType uint32, certEncoded *byte, encodedLen uint32) (context *CertContext, err error) [failretval==nil] = crypt32.CertCreateCertificateContext
   218  //sys   CertFreeCertificateContext(ctx *CertContext) (err error) = crypt32.CertFreeCertificateContext
   219  //sys   CertVerifyCertificateChainPolicy(policyOID uintptr, chain *CertChainContext, para *CertChainPolicyPara, status *CertChainPolicyStatus) (err error) = crypt32.CertVerifyCertificateChainPolicy
   220  //sys	RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno error) = advapi32.RegOpenKeyExW
   221  //sys	RegCloseKey(key Handle) (regerrno error) = advapi32.RegCloseKey
   222  //sys	RegQueryInfoKey(key Handle, class *uint16, classLen *uint32, reserved *uint32, subkeysLen *uint32, maxSubkeyLen *uint32, maxClassLen *uint32, valuesLen *uint32, maxValueNameLen *uint32, maxValueLen *uint32, saLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegQueryInfoKeyW
   223  //sys	RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegEnumKeyExW
   224  //sys	RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno error) = advapi32.RegQueryValueExW
   225  //sys	getCurrentProcessId() (pid uint32) = kernel32.GetCurrentProcessId
   226  //sys	GetConsoleMode(console Handle, mode *uint32) (err error) = kernel32.GetConsoleMode
   227  //sys	WriteConsole(console Handle, buf *uint16, towrite uint32, written *uint32, reserved *byte) (err error) = kernel32.WriteConsoleW
   228  //sys	ReadConsole(console Handle, buf *uint16, toread uint32, read *uint32, inputControl *byte) (err error) = kernel32.ReadConsoleW
   229  //sys	CreateToolhelp32Snapshot(flags uint32, processId uint32) (handle Handle, err error) [failretval==InvalidHandle] = kernel32.CreateToolhelp32Snapshot
   230  //sys	Process32First(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32FirstW
   231  //sys	Process32Next(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32NextW
   232  //sys	DeviceIoControl(handle Handle, ioControlCode uint32, inBuffer *byte, inBufferSize uint32, outBuffer *byte, outBufferSize uint32, bytesReturned *uint32, overlapped *Overlapped) (err error)
   233  // This function returns 1 byte BOOLEAN rather than the 4 byte BOOL.
   234  //sys	CreateSymbolicLink(symlinkfilename *uint16, targetfilename *uint16, flags uint32) (err error) [failretval&0xff==0] = CreateSymbolicLinkW
   235  //sys	CreateHardLink(filename *uint16, existingfilename *uint16, reserved uintptr) (err error) [failretval&0xff==0] = CreateHardLinkW
   236  
   237  // syscall interface implementation for other packages
   238  
   239  // Implemented in ../runtime/syscall_windows.go.
   240  func Exit(code int)
   241  
   242  func makeInheritSa() *SecurityAttributes {
   243  	var sa SecurityAttributes
   244  	sa.Length = uint32(unsafe.Sizeof(sa))
   245  	sa.InheritHandle = 1
   246  	return &sa
   247  }
   248  
   249  func Open(path string, mode int, perm uint32) (fd Handle, err error) {
   250  	if len(path) == 0 {
   251  		return InvalidHandle, ERROR_FILE_NOT_FOUND
   252  	}
   253  	pathp, err := UTF16PtrFromString(path)
   254  	if err != nil {
   255  		return InvalidHandle, err
   256  	}
   257  	var access uint32
   258  	switch mode & (O_RDONLY | O_WRONLY | O_RDWR) {
   259  	case O_RDONLY:
   260  		access = GENERIC_READ
   261  	case O_WRONLY:
   262  		access = GENERIC_WRITE
   263  	case O_RDWR:
   264  		access = GENERIC_READ | GENERIC_WRITE
   265  	}
   266  	if mode&O_CREAT != 0 {
   267  		access |= GENERIC_WRITE
   268  	}
   269  	if mode&O_APPEND != 0 {
   270  		access &^= GENERIC_WRITE
   271  		access |= FILE_APPEND_DATA
   272  	}
   273  	sharemode := uint32(FILE_SHARE_READ | FILE_SHARE_WRITE)
   274  	var sa *SecurityAttributes
   275  	if mode&O_CLOEXEC == 0 {
   276  		sa = makeInheritSa()
   277  	}
   278  	var createmode uint32
   279  	switch {
   280  	case mode&(O_CREAT|O_EXCL) == (O_CREAT | O_EXCL):
   281  		createmode = CREATE_NEW
   282  	case mode&(O_CREAT|O_TRUNC) == (O_CREAT | O_TRUNC):
   283  		createmode = CREATE_ALWAYS
   284  	case mode&O_CREAT == O_CREAT:
   285  		createmode = OPEN_ALWAYS
   286  	case mode&O_TRUNC == O_TRUNC:
   287  		createmode = TRUNCATE_EXISTING
   288  	default:
   289  		createmode = OPEN_EXISTING
   290  	}
   291  	h, e := CreateFile(pathp, access, sharemode, sa, createmode, FILE_ATTRIBUTE_NORMAL, 0)
   292  	return h, e
   293  }
   294  
   295  func Read(fd Handle, p []byte) (n int, err error) {
   296  	var done uint32
   297  	e := ReadFile(fd, p, &done, nil)
   298  	if e != nil {
   299  		if e == ERROR_BROKEN_PIPE {
   300  			// NOTE(brainman): work around ERROR_BROKEN_PIPE is returned on reading EOF from stdin
   301  			return 0, nil
   302  		}
   303  		return 0, e
   304  	}
   305  	if race.Enabled {
   306  		if done > 0 {
   307  			race.WriteRange(unsafe.Pointer(&p[0]), int(done))
   308  		}
   309  		race.Acquire(unsafe.Pointer(&ioSync))
   310  	}
   311  	if msanenabled && done > 0 {
   312  		msanWrite(unsafe.Pointer(&p[0]), int(done))
   313  	}
   314  	return int(done), nil
   315  }
   316  
   317  func Write(fd Handle, p []byte) (n int, err error) {
   318  	if race.Enabled {
   319  		race.ReleaseMerge(unsafe.Pointer(&ioSync))
   320  	}
   321  	var done uint32
   322  	e := WriteFile(fd, p, &done, nil)
   323  	if e != nil {
   324  		return 0, e
   325  	}
   326  	if race.Enabled && done > 0 {
   327  		race.ReadRange(unsafe.Pointer(&p[0]), int(done))
   328  	}
   329  	if msanenabled && done > 0 {
   330  		msanRead(unsafe.Pointer(&p[0]), int(done))
   331  	}
   332  	return int(done), nil
   333  }
   334  
   335  var ioSync int64
   336  
   337  func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
   338  	var w uint32
   339  	switch whence {
   340  	case 0:
   341  		w = FILE_BEGIN
   342  	case 1:
   343  		w = FILE_CURRENT
   344  	case 2:
   345  		w = FILE_END
   346  	}
   347  	hi := int32(offset >> 32)
   348  	lo := int32(offset)
   349  	// use GetFileType to check pipe, pipe can't do seek
   350  	ft, _ := GetFileType(fd)
   351  	if ft == FILE_TYPE_PIPE {
   352  		return 0, ESPIPE
   353  	}
   354  	rlo, e := SetFilePointer(fd, lo, &hi, w)
   355  	if e != nil {
   356  		return 0, e
   357  	}
   358  	return int64(hi)<<32 + int64(rlo), nil
   359  }
   360  
   361  func Close(fd Handle) (err error) {
   362  	return CloseHandle(fd)
   363  }
   364  
   365  var (
   366  	Stdin  = getStdHandle(STD_INPUT_HANDLE)
   367  	Stdout = getStdHandle(STD_OUTPUT_HANDLE)
   368  	Stderr = getStdHandle(STD_ERROR_HANDLE)
   369  )
   370  
   371  func getStdHandle(h int) (fd Handle) {
   372  	r, _ := GetStdHandle(h)
   373  	CloseOnExec(r)
   374  	return r
   375  }
   376  
   377  const ImplementsGetwd = true
   378  
   379  func Getwd() (wd string, err error) {
   380  	b := make([]uint16, 300)
   381  	n, e := GetCurrentDirectory(uint32(len(b)), &b[0])
   382  	if e != nil {
   383  		return "", e
   384  	}
   385  	return string(utf16.Decode(b[0:n])), nil
   386  }
   387  
   388  func Chdir(path string) (err error) {
   389  	pathp, err := UTF16PtrFromString(path)
   390  	if err != nil {
   391  		return err
   392  	}
   393  	return SetCurrentDirectory(pathp)
   394  }
   395  
   396  func Mkdir(path string, mode uint32) (err error) {
   397  	pathp, err := UTF16PtrFromString(path)
   398  	if err != nil {
   399  		return err
   400  	}
   401  	return CreateDirectory(pathp, nil)
   402  }
   403  
   404  func Rmdir(path string) (err error) {
   405  	pathp, err := UTF16PtrFromString(path)
   406  	if err != nil {
   407  		return err
   408  	}
   409  	return RemoveDirectory(pathp)
   410  }
   411  
   412  func Unlink(path string) (err error) {
   413  	pathp, err := UTF16PtrFromString(path)
   414  	if err != nil {
   415  		return err
   416  	}
   417  	return DeleteFile(pathp)
   418  }
   419  
   420  func Rename(oldpath, newpath string) (err error) {
   421  	from, err := UTF16PtrFromString(oldpath)
   422  	if err != nil {
   423  		return err
   424  	}
   425  	to, err := UTF16PtrFromString(newpath)
   426  	if err != nil {
   427  		return err
   428  	}
   429  	return MoveFile(from, to)
   430  }
   431  
   432  func ComputerName() (name string, err error) {
   433  	var n uint32 = MAX_COMPUTERNAME_LENGTH + 1
   434  	b := make([]uint16, n)
   435  	e := GetComputerName(&b[0], &n)
   436  	if e != nil {
   437  		return "", e
   438  	}
   439  	return string(utf16.Decode(b[0:n])), nil
   440  }
   441  
   442  func Ftruncate(fd Handle, length int64) (err error) {
   443  	curoffset, e := Seek(fd, 0, 1)
   444  	if e != nil {
   445  		return e
   446  	}
   447  	defer Seek(fd, curoffset, 0)
   448  	_, e = Seek(fd, length, 0)
   449  	if e != nil {
   450  		return e
   451  	}
   452  	e = SetEndOfFile(fd)
   453  	if e != nil {
   454  		return e
   455  	}
   456  	return nil
   457  }
   458  
   459  func Gettimeofday(tv *Timeval) (err error) {
   460  	var ft Filetime
   461  	GetSystemTimeAsFileTime(&ft)
   462  	*tv = NsecToTimeval(ft.Nanoseconds())
   463  	return nil
   464  }
   465  
   466  func Pipe(p []Handle) (err error) {
   467  	if len(p) != 2 {
   468  		return EINVAL
   469  	}
   470  	var r, w Handle
   471  	e := CreatePipe(&r, &w, makeInheritSa(), 0)
   472  	if e != nil {
   473  		return e
   474  	}
   475  	p[0] = r
   476  	p[1] = w
   477  	return nil
   478  }
   479  
   480  func Utimes(path string, tv []Timeval) (err error) {
   481  	if len(tv) != 2 {
   482  		return EINVAL
   483  	}
   484  	pathp, e := UTF16PtrFromString(path)
   485  	if e != nil {
   486  		return e
   487  	}
   488  	h, e := CreateFile(pathp,
   489  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   490  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   491  	if e != nil {
   492  		return e
   493  	}
   494  	defer Close(h)
   495  	a := NsecToFiletime(tv[0].Nanoseconds())
   496  	w := NsecToFiletime(tv[1].Nanoseconds())
   497  	return SetFileTime(h, nil, &a, &w)
   498  }
   499  
   500  func UtimesNano(path string, ts []Timespec) (err error) {
   501  	if len(ts) != 2 {
   502  		return EINVAL
   503  	}
   504  	pathp, e := UTF16PtrFromString(path)
   505  	if e != nil {
   506  		return e
   507  	}
   508  	h, e := CreateFile(pathp,
   509  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   510  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   511  	if e != nil {
   512  		return e
   513  	}
   514  	defer Close(h)
   515  	a := NsecToFiletime(TimespecToNsec(ts[0]))
   516  	w := NsecToFiletime(TimespecToNsec(ts[1]))
   517  	return SetFileTime(h, nil, &a, &w)
   518  }
   519  
   520  func Fsync(fd Handle) (err error) {
   521  	return FlushFileBuffers(fd)
   522  }
   523  
   524  func Chmod(path string, mode uint32) (err error) {
   525  	if mode == 0 {
   526  		return EINVAL
   527  	}
   528  	p, e := UTF16PtrFromString(path)
   529  	if e != nil {
   530  		return e
   531  	}
   532  	attrs, e := GetFileAttributes(p)
   533  	if e != nil {
   534  		return e
   535  	}
   536  	if mode&S_IWRITE != 0 {
   537  		attrs &^= FILE_ATTRIBUTE_READONLY
   538  	} else {
   539  		attrs |= FILE_ATTRIBUTE_READONLY
   540  	}
   541  	return SetFileAttributes(p, attrs)
   542  }
   543  
   544  func LoadCancelIoEx() error {
   545  	return procCancelIoEx.Find()
   546  }
   547  
   548  func LoadSetFileCompletionNotificationModes() error {
   549  	return procSetFileCompletionNotificationModes.Find()
   550  }
   551  
   552  // net api calls
   553  
   554  const socket_error = uintptr(^uint32(0))
   555  
   556  //sys	WSAStartup(verreq uint32, data *WSAData) (sockerr error) = ws2_32.WSAStartup
   557  //sys	WSACleanup() (err error) [failretval==socket_error] = ws2_32.WSACleanup
   558  //sys	WSAIoctl(s Handle, iocc uint32, inbuf *byte, cbif uint32, outbuf *byte, cbob uint32, cbbr *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) [failretval==socket_error] = ws2_32.WSAIoctl
   559  //sys	socket(af int32, typ int32, protocol int32) (handle Handle, err error) [failretval==InvalidHandle] = ws2_32.socket
   560  //sys	Setsockopt(s Handle, level int32, optname int32, optval *byte, optlen int32) (err error) [failretval==socket_error] = ws2_32.setsockopt
   561  //sys	Getsockopt(s Handle, level int32, optname int32, optval *byte, optlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockopt
   562  //sys	bind(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.bind
   563  //sys	connect(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.connect
   564  //sys	getsockname(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockname
   565  //sys	getpeername(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getpeername
   566  //sys	listen(s Handle, backlog int32) (err error) [failretval==socket_error] = ws2_32.listen
   567  //sys	shutdown(s Handle, how int32) (err error) [failretval==socket_error] = ws2_32.shutdown
   568  //sys	Closesocket(s Handle) (err error) [failretval==socket_error] = ws2_32.closesocket
   569  //sys	AcceptEx(ls Handle, as Handle, buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, recvd *uint32, overlapped *Overlapped) (err error) = mswsock.AcceptEx
   570  //sys	GetAcceptExSockaddrs(buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, lrsa **RawSockaddrAny, lrsalen *int32, rrsa **RawSockaddrAny, rrsalen *int32) = mswsock.GetAcceptExSockaddrs
   571  //sys	WSARecv(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecv
   572  //sys	WSASend(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASend
   573  //sys	WSARecvFrom(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32,  from *RawSockaddrAny, fromlen *int32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecvFrom
   574  //sys	WSASendTo(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *RawSockaddrAny, tolen int32,  overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASendTo
   575  //sys	GetHostByName(name string) (h *Hostent, err error) [failretval==nil] = ws2_32.gethostbyname
   576  //sys	GetServByName(name string, proto string) (s *Servent, err error) [failretval==nil] = ws2_32.getservbyname
   577  //sys	Ntohs(netshort uint16) (u uint16) = ws2_32.ntohs
   578  //sys	GetProtoByName(name string) (p *Protoent, err error) [failretval==nil] = ws2_32.getprotobyname
   579  //sys	DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status error) = dnsapi.DnsQuery_W
   580  //sys	DnsRecordListFree(rl *DNSRecord, freetype uint32) = dnsapi.DnsRecordListFree
   581  //sys	DnsNameCompare(name1 *uint16, name2 *uint16) (same bool) = dnsapi.DnsNameCompare_W
   582  //sys	GetAddrInfoW(nodename *uint16, servicename *uint16, hints *AddrinfoW, result **AddrinfoW) (sockerr error) = ws2_32.GetAddrInfoW
   583  //sys	FreeAddrInfoW(addrinfo *AddrinfoW) = ws2_32.FreeAddrInfoW
   584  //sys	GetIfEntry(pIfRow *MibIfRow) (errcode error) = iphlpapi.GetIfEntry
   585  //sys	GetAdaptersInfo(ai *IpAdapterInfo, ol *uint32) (errcode error) = iphlpapi.GetAdaptersInfo
   586  //sys	SetFileCompletionNotificationModes(handle Handle, flags uint8) (err error) = kernel32.SetFileCompletionNotificationModes
   587  //sys	WSAEnumProtocols(protocols *int32, protocolBuffer *WSAProtocolInfo, bufferLength *uint32) (n int32, err error) [failretval==-1] = ws2_32.WSAEnumProtocolsW
   588  
   589  // For testing: clients can set this flag to force
   590  // creation of IPv6 sockets to return EAFNOSUPPORT.
   591  var SocketDisableIPv6 bool
   592  
   593  type RawSockaddrInet4 struct {
   594  	Family uint16
   595  	Port   uint16
   596  	Addr   [4]byte /* in_addr */
   597  	Zero   [8]uint8
   598  }
   599  
   600  type RawSockaddrInet6 struct {
   601  	Family   uint16
   602  	Port     uint16
   603  	Flowinfo uint32
   604  	Addr     [16]byte /* in6_addr */
   605  	Scope_id uint32
   606  }
   607  
   608  type RawSockaddr struct {
   609  	Family uint16
   610  	Data   [14]int8
   611  }
   612  
   613  type RawSockaddrAny struct {
   614  	Addr RawSockaddr
   615  	Pad  [96]int8
   616  }
   617  
   618  type Sockaddr interface {
   619  	sockaddr() (ptr unsafe.Pointer, len int32, err error) // lowercase; only we can define Sockaddrs
   620  }
   621  
   622  type SockaddrInet4 struct {
   623  	Port int
   624  	Addr [4]byte
   625  	raw  RawSockaddrInet4
   626  }
   627  
   628  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, int32, error) {
   629  	if sa.Port < 0 || sa.Port > 0xFFFF {
   630  		return nil, 0, EINVAL
   631  	}
   632  	sa.raw.Family = AF_INET
   633  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   634  	p[0] = byte(sa.Port >> 8)
   635  	p[1] = byte(sa.Port)
   636  	for i := 0; i < len(sa.Addr); i++ {
   637  		sa.raw.Addr[i] = sa.Addr[i]
   638  	}
   639  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   640  }
   641  
   642  type SockaddrInet6 struct {
   643  	Port   int
   644  	ZoneId uint32
   645  	Addr   [16]byte
   646  	raw    RawSockaddrInet6
   647  }
   648  
   649  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, int32, error) {
   650  	if sa.Port < 0 || sa.Port > 0xFFFF {
   651  		return nil, 0, EINVAL
   652  	}
   653  	sa.raw.Family = AF_INET6
   654  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   655  	p[0] = byte(sa.Port >> 8)
   656  	p[1] = byte(sa.Port)
   657  	sa.raw.Scope_id = sa.ZoneId
   658  	for i := 0; i < len(sa.Addr); i++ {
   659  		sa.raw.Addr[i] = sa.Addr[i]
   660  	}
   661  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   662  }
   663  
   664  type SockaddrUnix struct {
   665  	Name string
   666  }
   667  
   668  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, int32, error) {
   669  	// TODO(brainman): implement SockaddrUnix.sockaddr()
   670  	return nil, 0, EWINDOWS
   671  }
   672  
   673  func (rsa *RawSockaddrAny) Sockaddr() (Sockaddr, error) {
   674  	switch rsa.Addr.Family {
   675  	case AF_UNIX:
   676  		return nil, EWINDOWS
   677  
   678  	case AF_INET:
   679  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
   680  		sa := new(SockaddrInet4)
   681  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   682  		sa.Port = int(p[0])<<8 + int(p[1])
   683  		for i := 0; i < len(sa.Addr); i++ {
   684  			sa.Addr[i] = pp.Addr[i]
   685  		}
   686  		return sa, nil
   687  
   688  	case AF_INET6:
   689  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
   690  		sa := new(SockaddrInet6)
   691  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   692  		sa.Port = int(p[0])<<8 + int(p[1])
   693  		sa.ZoneId = pp.Scope_id
   694  		for i := 0; i < len(sa.Addr); i++ {
   695  			sa.Addr[i] = pp.Addr[i]
   696  		}
   697  		return sa, nil
   698  	}
   699  	return nil, EAFNOSUPPORT
   700  }
   701  
   702  func Socket(domain, typ, proto int) (fd Handle, err error) {
   703  	if domain == AF_INET6 && SocketDisableIPv6 {
   704  		return InvalidHandle, EAFNOSUPPORT
   705  	}
   706  	return socket(int32(domain), int32(typ), int32(proto))
   707  }
   708  
   709  func SetsockoptInt(fd Handle, level, opt int, value int) (err error) {
   710  	v := int32(value)
   711  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&v)), int32(unsafe.Sizeof(v)))
   712  }
   713  
   714  func Bind(fd Handle, sa Sockaddr) (err error) {
   715  	ptr, n, err := sa.sockaddr()
   716  	if err != nil {
   717  		return err
   718  	}
   719  	return bind(fd, ptr, n)
   720  }
   721  
   722  func Connect(fd Handle, sa Sockaddr) (err error) {
   723  	ptr, n, err := sa.sockaddr()
   724  	if err != nil {
   725  		return err
   726  	}
   727  	return connect(fd, ptr, n)
   728  }
   729  
   730  func Getsockname(fd Handle) (sa Sockaddr, err error) {
   731  	var rsa RawSockaddrAny
   732  	l := int32(unsafe.Sizeof(rsa))
   733  	if err = getsockname(fd, &rsa, &l); err != nil {
   734  		return
   735  	}
   736  	return rsa.Sockaddr()
   737  }
   738  
   739  func Getpeername(fd Handle) (sa Sockaddr, err error) {
   740  	var rsa RawSockaddrAny
   741  	l := int32(unsafe.Sizeof(rsa))
   742  	if err = getpeername(fd, &rsa, &l); err != nil {
   743  		return
   744  	}
   745  	return rsa.Sockaddr()
   746  }
   747  
   748  func Listen(s Handle, n int) (err error) {
   749  	return listen(s, int32(n))
   750  }
   751  
   752  func Shutdown(fd Handle, how int) (err error) {
   753  	return shutdown(fd, int32(how))
   754  }
   755  
   756  func WSASendto(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to Sockaddr, overlapped *Overlapped, croutine *byte) (err error) {
   757  	rsa, l, err := to.sockaddr()
   758  	if err != nil {
   759  		return err
   760  	}
   761  	return WSASendTo(s, bufs, bufcnt, sent, flags, (*RawSockaddrAny)(unsafe.Pointer(rsa)), l, overlapped, croutine)
   762  }
   763  
   764  func LoadGetAddrInfo() error {
   765  	return procGetAddrInfoW.Find()
   766  }
   767  
   768  var connectExFunc struct {
   769  	once sync.Once
   770  	addr uintptr
   771  	err  error
   772  }
   773  
   774  func LoadConnectEx() error {
   775  	connectExFunc.once.Do(func() {
   776  		var s Handle
   777  		s, connectExFunc.err = Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)
   778  		if connectExFunc.err != nil {
   779  			return
   780  		}
   781  		defer CloseHandle(s)
   782  		var n uint32
   783  		connectExFunc.err = WSAIoctl(s,
   784  			SIO_GET_EXTENSION_FUNCTION_POINTER,
   785  			(*byte)(unsafe.Pointer(&WSAID_CONNECTEX)),
   786  			uint32(unsafe.Sizeof(WSAID_CONNECTEX)),
   787  			(*byte)(unsafe.Pointer(&connectExFunc.addr)),
   788  			uint32(unsafe.Sizeof(connectExFunc.addr)),
   789  			&n, nil, 0)
   790  	})
   791  	return connectExFunc.err
   792  }
   793  
   794  func connectEx(s Handle, name unsafe.Pointer, namelen int32, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) (err error) {
   795  	r1, _, e1 := Syscall9(connectExFunc.addr, 7, uintptr(s), uintptr(name), uintptr(namelen), uintptr(unsafe.Pointer(sendBuf)), uintptr(sendDataLen), uintptr(unsafe.Pointer(bytesSent)), uintptr(unsafe.Pointer(overlapped)), 0, 0)
   796  	if r1 == 0 {
   797  		if e1 != 0 {
   798  			err = error(e1)
   799  		} else {
   800  			err = EINVAL
   801  		}
   802  	}
   803  	return
   804  }
   805  
   806  func ConnectEx(fd Handle, sa Sockaddr, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) error {
   807  	err := LoadConnectEx()
   808  	if err != nil {
   809  		return errorspkg.New("failed to find ConnectEx: " + err.Error())
   810  	}
   811  	ptr, n, err := sa.sockaddr()
   812  	if err != nil {
   813  		return err
   814  	}
   815  	return connectEx(fd, ptr, n, sendBuf, sendDataLen, bytesSent, overlapped)
   816  }
   817  
   818  // Invented structures to support what package os expects.
   819  type Rusage struct {
   820  	CreationTime Filetime
   821  	ExitTime     Filetime
   822  	KernelTime   Filetime
   823  	UserTime     Filetime
   824  }
   825  
   826  type WaitStatus struct {
   827  	ExitCode uint32
   828  }
   829  
   830  func (w WaitStatus) Exited() bool { return true }
   831  
   832  func (w WaitStatus) ExitStatus() int { return int(w.ExitCode) }
   833  
   834  func (w WaitStatus) Signal() Signal { return -1 }
   835  
   836  func (w WaitStatus) CoreDump() bool { return false }
   837  
   838  func (w WaitStatus) Stopped() bool { return false }
   839  
   840  func (w WaitStatus) Continued() bool { return false }
   841  
   842  func (w WaitStatus) StopSignal() Signal { return -1 }
   843  
   844  func (w WaitStatus) Signaled() bool { return false }
   845  
   846  func (w WaitStatus) TrapCause() int { return -1 }
   847  
   848  // Timespec is an invented structure on Windows, but here for
   849  // consistency with the syscall package for other operating systems.
   850  type Timespec struct {
   851  	Sec  int64
   852  	Nsec int64
   853  }
   854  
   855  func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
   856  
   857  func NsecToTimespec(nsec int64) (ts Timespec) {
   858  	ts.Sec = nsec / 1e9
   859  	ts.Nsec = nsec % 1e9
   860  	return
   861  }
   862  
   863  // TODO(brainman): fix all needed for net
   864  
   865  func Accept(fd Handle) (nfd Handle, sa Sockaddr, err error) { return 0, nil, EWINDOWS }
   866  func Recvfrom(fd Handle, p []byte, flags int) (n int, from Sockaddr, err error) {
   867  	return 0, nil, EWINDOWS
   868  }
   869  func Sendto(fd Handle, p []byte, flags int, to Sockaddr) (err error)       { return EWINDOWS }
   870  func SetsockoptTimeval(fd Handle, level, opt int, tv *Timeval) (err error) { return EWINDOWS }
   871  
   872  // The Linger struct is wrong but we only noticed after Go 1.
   873  // sysLinger is the real system call structure.
   874  
   875  // BUG(brainman): The definition of Linger is not appropriate for direct use
   876  // with Setsockopt and Getsockopt.
   877  // Use SetsockoptLinger instead.
   878  
   879  type Linger struct {
   880  	Onoff  int32
   881  	Linger int32
   882  }
   883  
   884  type sysLinger struct {
   885  	Onoff  uint16
   886  	Linger uint16
   887  }
   888  
   889  type IPMreq struct {
   890  	Multiaddr [4]byte /* in_addr */
   891  	Interface [4]byte /* in_addr */
   892  }
   893  
   894  type IPv6Mreq struct {
   895  	Multiaddr [16]byte /* in6_addr */
   896  	Interface uint32
   897  }
   898  
   899  func GetsockoptInt(fd Handle, level, opt int) (int, error) { return -1, EWINDOWS }
   900  
   901  func SetsockoptLinger(fd Handle, level, opt int, l *Linger) (err error) {
   902  	sys := sysLinger{Onoff: uint16(l.Onoff), Linger: uint16(l.Linger)}
   903  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&sys)), int32(unsafe.Sizeof(sys)))
   904  }
   905  
   906  func SetsockoptInet4Addr(fd Handle, level, opt int, value [4]byte) (err error) {
   907  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&value[0])), 4)
   908  }
   909  func SetsockoptIPMreq(fd Handle, level, opt int, mreq *IPMreq) (err error) {
   910  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(mreq)), int32(unsafe.Sizeof(*mreq)))
   911  }
   912  func SetsockoptIPv6Mreq(fd Handle, level, opt int, mreq *IPv6Mreq) (err error) { return EWINDOWS }
   913  
   914  func Getpid() (pid int) { return int(getCurrentProcessId()) }
   915  
   916  func FindFirstFile(name *uint16, data *Win32finddata) (handle Handle, err error) {
   917  	// NOTE(rsc): The Win32finddata struct is wrong for the system call:
   918  	// the two paths are each one uint16 short. Use the correct struct,
   919  	// a win32finddata1, and then copy the results out.
   920  	// There is no loss of expressivity here, because the final
   921  	// uint16, if it is used, is supposed to be a NUL, and Go doesn't need that.
   922  	// For Go 1.1, we might avoid the allocation of win32finddata1 here
   923  	// by adding a final Bug [2]uint16 field to the struct and then
   924  	// adjusting the fields in the result directly.
   925  	var data1 win32finddata1
   926  	handle, err = findFirstFile1(name, &data1)
   927  	if err == nil {
   928  		copyFindData(data, &data1)
   929  	}
   930  	return
   931  }
   932  
   933  func FindNextFile(handle Handle, data *Win32finddata) (err error) {
   934  	var data1 win32finddata1
   935  	err = findNextFile1(handle, &data1)
   936  	if err == nil {
   937  		copyFindData(data, &data1)
   938  	}
   939  	return
   940  }
   941  
   942  func getProcessEntry(pid int) (*ProcessEntry32, error) {
   943  	snapshot, err := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
   944  	if err != nil {
   945  		return nil, err
   946  	}
   947  	defer CloseHandle(snapshot)
   948  	var procEntry ProcessEntry32
   949  	procEntry.Size = uint32(unsafe.Sizeof(procEntry))
   950  	if err = Process32First(snapshot, &procEntry); err != nil {
   951  		return nil, err
   952  	}
   953  	for {
   954  		if procEntry.ProcessID == uint32(pid) {
   955  			return &procEntry, nil
   956  		}
   957  		err = Process32Next(snapshot, &procEntry)
   958  		if err != nil {
   959  			return nil, err
   960  		}
   961  	}
   962  }
   963  
   964  func Getppid() (ppid int) {
   965  	pe, err := getProcessEntry(Getpid())
   966  	if err != nil {
   967  		return -1
   968  	}
   969  	return int(pe.ParentProcessID)
   970  }
   971  
   972  // TODO(brainman): fix all needed for os
   973  func Fchdir(fd Handle) (err error)             { return EWINDOWS }
   974  func Link(oldpath, newpath string) (err error) { return EWINDOWS }
   975  func Symlink(path, link string) (err error)    { return EWINDOWS }
   976  
   977  func Fchmod(fd Handle, mode uint32) (err error)        { return EWINDOWS }
   978  func Chown(path string, uid int, gid int) (err error)  { return EWINDOWS }
   979  func Lchown(path string, uid int, gid int) (err error) { return EWINDOWS }
   980  func Fchown(fd Handle, uid int, gid int) (err error)   { return EWINDOWS }
   981  
   982  func Getuid() (uid int)                  { return -1 }
   983  func Geteuid() (euid int)                { return -1 }
   984  func Getgid() (gid int)                  { return -1 }
   985  func Getegid() (egid int)                { return -1 }
   986  func Getgroups() (gids []int, err error) { return nil, EWINDOWS }
   987  
   988  type Signal int
   989  
   990  func (s Signal) Signal() {}
   991  
   992  func (s Signal) String() string {
   993  	if 0 <= s && int(s) < len(signals) {
   994  		str := signals[s]
   995  		if str != "" {
   996  			return str
   997  		}
   998  	}
   999  	return "signal " + itoa(int(s))
  1000  }
  1001  
  1002  func LoadCreateSymbolicLink() error {
  1003  	return procCreateSymbolicLinkW.Find()
  1004  }
  1005  
  1006  // Readlink returns the destination of the named symbolic link.
  1007  func Readlink(path string, buf []byte) (n int, err error) {
  1008  	fd, err := CreateFile(StringToUTF16Ptr(path), GENERIC_READ, 0, nil, OPEN_EXISTING,
  1009  		FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, 0)
  1010  	if err != nil {
  1011  		return -1, err
  1012  	}
  1013  	defer CloseHandle(fd)
  1014  
  1015  	rdbbuf := make([]byte, MAXIMUM_REPARSE_DATA_BUFFER_SIZE)
  1016  	var bytesReturned uint32
  1017  	err = DeviceIoControl(fd, FSCTL_GET_REPARSE_POINT, nil, 0, &rdbbuf[0], uint32(len(rdbbuf)), &bytesReturned, nil)
  1018  	if err != nil {
  1019  		return -1, err
  1020  	}
  1021  
  1022  	rdb := (*reparseDataBuffer)(unsafe.Pointer(&rdbbuf[0]))
  1023  	var s string
  1024  	switch rdb.ReparseTag {
  1025  	case IO_REPARSE_TAG_SYMLINK:
  1026  		data := (*symbolicLinkReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1027  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1028  		s = UTF16ToString(p[data.SubstituteNameOffset/2 : (data.SubstituteNameOffset+data.SubstituteNameLength)/2])
  1029  		if data.Flags&_SYMLINK_FLAG_RELATIVE == 0 {
  1030  			if len(s) >= 4 && s[:4] == `\??\` {
  1031  				s = s[4:]
  1032  				switch {
  1033  				case len(s) >= 2 && s[1] == ':': // \??\C:\foo\bar
  1034  					// do nothing
  1035  				case len(s) >= 4 && s[:4] == `UNC\`: // \??\UNC\foo\bar
  1036  					s = `\\` + s[4:]
  1037  				default:
  1038  					// unexpected; do nothing
  1039  				}
  1040  			} else {
  1041  				// unexpected; do nothing
  1042  			}
  1043  		}
  1044  	case _IO_REPARSE_TAG_MOUNT_POINT:
  1045  		data := (*mountPointReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1046  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1047  		s = UTF16ToString(p[data.SubstituteNameOffset/2 : (data.SubstituteNameOffset+data.SubstituteNameLength)/2])
  1048  		if len(s) >= 4 && s[:4] == `\??\` { // \??\C:\foo\bar
  1049  			s = s[4:]
  1050  		} else {
  1051  			// unexpected; do nothing
  1052  		}
  1053  	default:
  1054  		// the path is not a symlink or junction but another type of reparse
  1055  		// point
  1056  		return -1, ENOENT
  1057  	}
  1058  	n = copy(buf, []byte(s))
  1059  
  1060  	return n, nil
  1061  }